1) Field of the Invention
The present invention relates to a dental implant having a plurality of split fins that are vertically spaced along the vertical axis of the fixture portion of the implant. These split fins hold the fixture portion of a dental implant stationary within the patient's jaw by engaging the patient's jawbone and promoting osseointegration—the growth bone around and on the surface of the implant. Each split fin has a first end that is vertically spaced from a second end along the fixture's vertical axis such that the split fin extends from the first end and around the fixture's circumference along an inclined plane until it terminates at the second end so that the split fin creates a single spiral that extends around the entire circumference of the fixture portion of the implant. These split fins, by engaging the bone, form compartments along the length of the implant body. These compartments are “healing chambers” that allow isolation from outside influences such as microbes, chemicals or other potential irritants that may interfere with bone formation.
2) Description of Related Art
For almost as long as dental implants have been used and known in the art, two general types of implants have been used. A screw type implant shown in FIG. 1 and a fin type implant shown in FIG. 2. There are advantages and disadvantages to both types of implants. The screw type implant uses threads A that wrap around the circumference of the implant body B along an inclined plane. The threads A engage the surrounding bone in much the same fashion as a screw would engage the wood into which it is screwed.
The advantage of using a screw type implant is that it provides immediate stability to the implant due to the manner in which the threads A engage the patient's jaw bone. Thus, a screw type implant may be used almost immediately after placement in the patient's jaw. There are at least two disadvantages associated with the screw type implant. The first is that the use of a screw type implant increases the risk of the patient suffering from peri-implantitis, an infection, which if not properly and timely treated can lead to the failure of the implant. Screw type implants, especially those used on the patient's lower jaw allow bacteria such as streptococci, which has a round or generally spherical shape, to travel down the threads of the implant until it reaches the bottom of the implant. Once the bacteria has reached the bottom of the implant, it can then cause infection deep in the patient's jaw bone. This type of infection is a major concern when using a screw type implant from both a health and implant failure perspective. The body responds to this irritation by encapsulating the implant in reactive connective tissue which prevents bone formation at the surface of the implant.
Another disadvantage of the screw type implant is that cortical-like Haversian bone rarely forms on screw type implants during osseointegration. This is due to the fact that when inserted into the patient's jaw, the thread of a screw type implant creates one long open channel leading from the surface of the jawbone to the bottom of the implant opening created in the patient's jawbone. As osseointegration occurs, lamellar bone, which is also known as interstitial type bone, develops along the channel created by the thread and around the implant. Because there is no interruption in the channel created by the thread, there can be no healing chamber or healing compartments created in the patient's jawbone. This healing chamber or healing compartment is necessary for cortical-like bone, which is also known as Haversian bone, to develop around the implant. The development of the cortical-like bone is desirable because this bone has more intimate contact with the implant surface and improved mechanical properties such as being harder and more dense that, over time, will continue to improve. Therefore, another disadvantage of the screw type implant is that the cortical-like bone is not likely to develop around the implant as is desired.
Another disadvantage associated with the screw type implant is that forces normally associated with chewing food can over time cause the implant to come unscrewed and to work its way back out of the patient's jaw. To prevent this from happening, an anti-rotational groove C is often cut into the bottom most thread of the implant. This anti-rotational groove C is generally wedge shaped and allows bone to grow within the groove, thus, preventing the implant from coming unscrewed or backing out of the patient's jaw.
While the fin type implant shown in FIG. 2 addresses some of the disadvantages of the screw type implant, it has its own disadvantages too. The fin type implant uses a number of circular disc-shaped fins D that wrap around and enclose the entire circumference of the implant body E. These fins D are vertically spaced from one another along the vertical axis of the implant body E and are generally parallel to one another. In some instances, each of the fins has the same diameter. In other instances, the fins can have decreasing diameter to give the fin type implant a generally conical shape. The fins lessen a patient's risk of the patient suffering from peri-implantitis by removing the inclined plane along which the threads wrap around the implant body. As osseointegration occurs, the fins create a number of sealed compartments so that bacteria that develops on one fin cannot travel down to the next fin. This allows the body to fight and defeat any infection without allowing the infection to spread further into the patient's jawbone.
As discussed above, the creation of separate healing chambers or healing compartments promotes the development of cortical like bone. Because the fin type implant creates such chambers, it is well suited for the development of cortical-like bone.
The fin type implant also removes the need for inclusion of an anti-rotational groove. Because the fin type implant is inserted rather than screwed into the patient's jaw, there is no risk that the implant will come unscrewed as osseointegration occurs.
The major disadvantage of the fin type implant is that the implant has very little initial stability in the patient's jaw. Unlike a screw type implant that immediately engages the bone through the use of threads, a fin type implant is inserted into a hole that has been created in the patient's jaw that has the same or slightly larger diameter than the fin type implant. Upon insertion, the fin type implant will remain relatively loose and/or susceptible to movement within the patient's jaw. Until osseointegration has occurred, forces normally associated with chewing will cause a newly installed fin type implant to wiggle or move about too much to provide immediate functionality of the implant. This inherent instability encourages the formation of a fibrous capsule around the implant and prevents bone formation at the implant surface. Instead, the fin type implant will not be adequately functional until osseointegration has occurred over a period of time, typically 4-5 months.
Accordingly, it is an object of the present invention to provide an implant that will provide a high level of initial stability so that the implant will be functional shortly after being placed in the patient's jaw bone, while at the same time creating the desirable healing compartments.
Accordingly, it is an object of the present invention to provide an implant that will reduce the risk of a patient developing infections such as peri-implantitis.
Accordingly, it is an object of the present invention to provide an implant that will reduce the risk that bacteria will travel down the implant body or spread to the patient's jaw bone.
Accordingly, it is an object of the present invention to provide an implant that will promote the formation of cortical-like bone during the osseointegration process.
Accordingly, it is an object of the present invention to provide an implant that can easily be incorporated into all existing root-form implant systems, regardless of the material used in the implant.